Tube bending tool

ABSTRACT

A universally adjustable tube abutment for a hand operated tube bending tool to accommodate tubes in which bends are to be placed in various planes.

United States Patent lnventors Emery J. Zahuranec Solon;

Zoltan Szohatzky, Mentor; Harry G. Dodge, Painesville, Ohio Nov. 12, 1968 Apr. 13, 1971 Crawford Fitting Company Solon, Ohio Appl, No. Filed Patented Assignee TUBE BENDINC TOOL 9 Claims, 7 Drawing Figs.

US. Cl 72/311,

72/152, 72/217, 72/406 Int. Cl B2ld 11/04 [50] Field of Search 72/149, l52l54,217, 218, 304, 306, 311, 318, 319, 369,

[56] References Cited UNITED STATES PATENTS 3,417,594 12/1968 Zahuranec et al. 72/217 3,236,082 2/1966 Beck et al. 72/149 3,004,583 10/1961 Zuccala et al. 72/150 Primary Examiner-Richard .l. Herbst Assistant ExaminerMichael J. Keenan Att0rneyFay, Sharpe and Mulholland ABSTRACT: A universally adjustable tube abutment for a hand operated tube bending tool to accommodate tubes in which bends are to be placed in various planes.

Pgtentd April 13-, 1911 2 sheets-sheet :L

FIG.I

ATTORNEYS.

Patentd *April 13, 1971 2 Sheets-Sheet 2 FIG.7

FIG.6

Y J AN ATTQRNEYS.

TUBE BENDING TOOL BACKGROUND OF THE INVENTION This invention relates to an improvement in hand operated tube bending tools and more particularly relates to an improved design of the tool such that compound bends may be placed in a length of tubing.

Various types of hand operated tube bending tools have been devised in the past. Samples of prior art teachings are U.S. Pat. No.' 3,004,583 to Zuccala et al., US. Pat. No. 3,236,082 to Beck et al. As illustrated in these patents, the tube is inserted in the tube bending tool and the end of the tube is drawn around a mandrel to form the desired bend. Although the angle of the bend in the tube may be varied, these prior art tools are restricted to placing bends in the tube in but a single plane.

SUMMARY OF THE INVENTION This invention is directed to a tube bending tool provided with a tube abutment means so constructed as to permit compound bending operations. More particularly, this invention is directed to a universally adjustable tube abutment means for a tube bending tool thus to accommodate bends in various planes.

The tube abutment means comprises a block carrier or support member with means securing the block carrier to the bar of the tube bending tool for movement relative thereto. A support rod is carried by the block carrier, and a tube abutment block is carried by the support rod. The block carrier is capable of movement both longitudinally of the bar of the tube bending tool, and about the longitudinal axis of such bar. The support rod is mounted in the block carrier for movement relative to the block carrier in a line parallel to the axis of the bar of the tube bending tool or about an axis of rotation paralleled to the axis of said bar.

The preferred embodiment of this invention will now be described with reference to the attached drawings in which:

FIG. 1 is a partial top plan view of a tube bending tool',

FIG. 2 is a perspective view of one embodiment of the tube abutment means of this invention;

FIG. 3 is a sectional view taken along the line 3-3 of FIG. 2;

FIG. 4 is an end view of the tube abutment block of FIG. 2 taken along the line 4-4 of FIG. 2;

FIG. 5 is a sectional view of the tube abutment block taken along the line 5-5 of FIG. 4;

FIG. 6 is a side view of the tube abutment block taken along the line 6-6 of FIG. 4;

FIG. 7 is a sectional view of a modified form of the tube abutment block and supporting rod of FIG. 2 illustrating a second embodiment of the tube abutment means of this invention.

DESCRIPTION OF THE INVENTION The present invention is shown and described in conjunction with a tube bending tool of the type illustrated in US. Pat. No. 3,004,583 to Zuccala et al., and to which reference is hereby made for a more complete description of one type of tube bending tool with which the invention may be used.

Turning now to FIG. 1 of the drawings there is shown, in brief, a tube bending tool, designated generally by the reference numeral 10. The tube bending tool 10 comprises a cover plate 11 with a shaft 12 extending therethrough. A tube forming roll or mandrel 13 is secured to the shaft 12 for rotation therewith. A peripheral groove 14 is formed in the man drel 13, the groove being adapted to engage a portion of the periphery of a tube. A gear 15 is secured to the shaft 12, and is in meshing engagement with a pinion 16. A handle 17 is operable to rotate the pinion 16 thereby to transmit rotation to the shaft 12 and the mandrel 13. Coaxial with the pinion 16 is a roller 18 which has a circumferential groove 19 also adapted to engage a portion of the tube periphery. An elongated bar 20 is secured to the mandrel 13, and carries a pivotally mounted hook 21. The tube abutment means 22, to which this invention pertains, is supported on the bar 20.

As is more fully described in the above-mentioned US. Pat. No. 3,004,583, the tube bending tool is employed by inserting a length of tubing between the roller 18 and a mandrel 13, with the tube being received in the grooves 14 and 19. The end of the tubing engages the tube abutment means 22 and the hook 21 embraces the circumference of the tube to retain the same in engagement with the roller 18 and the mandrel 13 during the bending operation. Rotation of the handle 17 causes rotation of the mandrel 13 and the elongated bar 20 about the shaft 12 as an axis of rotation. The hook 21 on bar 20 draws the tubing about the mandrel 13 thereby imparting a bend to the tubing. Adjustable stop 23 may be employed to limit the degree of bend placed in the tubing.

One embodiment of the tube abutment means which comprises the present invention is illustrated in FIG. 2. The tube abutment means 22 includes a block carrier or support member 24 received by means of a suitable bore 20a over the bar 20. A locking knob 25 is employed to clamp the block carrier on the bar 20. A support rod 26 is disposed within bore 26a in the block carrier such that the axis of the support rod is parallel to the axis of the bar. A locking knob 27 is employed to clamp the support rod to the block carrier. A tube stop pin 28 having a longitudinal axis parallel to the bar 20 is mounted by appropriate means to the block carrier 24 with an end portion projecting therefrom for a purpose to be described more fully hereafter. As is shown in FIG. 2, one end of support rod 26 carries a tube abutment block 29 for the purpose of engaging a tube 30.

As seen in FIG. 3, locking of the bar 20 and the support rod 26 to the block carrier 24 is achieved by means of a pair of locking earns 31. 32 disposed within suitable recesses in the block carrier. In each instance, such recesses communicate laterally with the respective support rod and bar receiving bores. Locking cams 31, 32 are generally cylindrical in shape and each includes a camming face 33 adapted to engage a respective bar 20 or support rod 26. Locking earns 31, 32 also include appropriate tapped holes for the purpose of receiving the threaded shank of a respective locking knob 25, 27. The locking knobs 25, 27 are threadedly received in washers 34 disposed within counterbores of the block carrier 24. Thus, rotation of either of the locking knobs 25, 27 produces movement of the respective locking earns 31, 32 within the block carrier to bring a camming face 33 into engagement with a respective bar 20 or support rod 26, thus to lock these members with respect to the block carrier 24. The camming face 33 of each of the locking earns 31, 32 takes generally the form of a section of a cylindrical surface defined on the exterior of such cams. The radius of curvature of the camming face 33 slightly exceeds the radius of curvature of the bar 20 and of the support rod 26 such that central positioning of the locking earns 31, 32 within the block carrier will permit free movement of the bar 20 and of the support rod 26 within the carri er. Actuation of locking knobs 25, 77 to produce a lifting of the locking cams 31, 32 in their recesses within the block carrier will cause the camming surface 33 to bind against a respective bar 20 or support rod 26, thus to lock these members firmly to the carrier.

It is readily apparent that with but two adjustments, the tube abutment means may be adjusted in at least four ways. Thus, by releasing the locking cam 31 which engages bar 20, block carrier 24 may be pivoted about the bar 20 in the direction of the arrow 34, or it may be moved longitudinally of the bar 20 in the direction of the arrow 35.

Locking knob 27 controls rotation of the support rod 26 about its axis, i.e. an axis parallel to the longitudinal axis of the bar 20 (see arrow 36). Locking knob 27 also controls the sliding movement of the support rod 26 within the block carrier 24 in a line parallel to the longitudinal axis of bar 20 as shown by the arrow 36'.

In the embodiment of FIGS. 1-6, the head of the tube abutment block 29 carries a central V-shaped groove 37, and

additional V-shaped grooves 38, 39 disposed at either end of the central groove. As is most clearly shown in FIGS. 4 and 5, the central V-shaped groove 37 is defined by a pair of sidewalls which intersect to form a bottom disposed generally perpendicular to the longitudinal axis of the support rod 26. V-shaped groove 38 is defined by a pair of sidewalls which intersect to form a bottom disposed at an angle of approximately 60 to the longitudinal axis of the suppon rod 26, and the walls of V-shaped groove 39 intersect to form a bottom positioned at an angle of approximately 45 to the longitudinal axis of such rod. As is seen in FIG. 6, the respective sidewalls of the V-shaped grooves 37, 38 and 39 are disposed at an angle of 45 with respect to the longitudinal axis of the support rod 26 thereby defining an included angle of 90.

The V-shaped grooves 37, 38 and 39 define tube abutment surfaces for the purpose of supporting tubing while completing compound bends. Thus as is shown in FIG. 2, a tube 30 provided with a 60 bend has a portion of its periphery disposed within the 60 V-groove 38, the walls of which provide a support for the tube for a subsequent bending operatron.

It will be apparent from an examination of FIG. 2 that the tube abutment block 29 is also capable of providing tube support for 90 and 45 bends. In this connection, should it be desired to perform a subsequent bending operation on a tube previously provided with a 45 bend, the tube abutment block 29 as shown in FIG. 2 is released by means of locking knob 27. Subsequently, the block is rotated 180 about its own axis such that V-groove 39 is disposed in an upward position to receive the periphery of the tube.

Since 30, 60, and 45 bends are quite common, the tube abutment block of FIG. 2 will accommodate those bends normally utilized in industry. Moreover, other bends may also be accommodated, although the portion of the tube periphery engaged by the block in such cases is not as substantial as in the bends previously mentioned.

Reference is now made to the tube stop pin 28 extending from the block carrier 24. When it is desired to place a first bend in a straight run of tubing, the tube end is disposed about the tube stop pin 28 while abutting the block carrier 24. Reference is made to FIG. I wherein a straight run of tubing 30 is shown disposed within the tube bending tool with the free end of the tube disposed about the tube stop pin. As was previously described, rotation of the handle 17 (FIG. l) causes rotation of the mandrel I3 thus to pivot the elongated bar about the axis of shaft 12 as the center of the axis of rotation. The tube stop pin 28 provides support for the tube end during this bending operation. In the event that a compound bend in the tube is desired, the tube abutment block 29 provides a means of support for the tube end. Thus, where desired, the tube abutment block 29 may be rotated about the axis of the support rod 26 by manipulation of the locking knob 27. Also, the distance between the tube abutment block 29 and the block carrier 24 may be adjusted by means of the locking knob 27.

To summarize the embodiment of FIG. 2, the block carrier 24 may be rotated about an axis of rotation coincident with the longitudinal axis of the bar 20 as shown by the arrow direction 34. The block carrier 24 also may be moved along a line parallel to the longitudinal axis of the bar 20 as is shown by the arrow 35. Movement of the block carrier 24 with respect to the bar 20 is achieved through manipulation of the locking knob 25 and actuation ofits locking cam 31. The support rod 26 may be rotated about its longitudinal axis through manipulation of the locking knob 27. Also, the tube abutment block 29 may be moved along a line of travel coincident with the longitudinal axis of the support rod 26 through manipulation of the locking knob 27. Thus, the abutment means of FIG. 2 is capable of providing several degrees of freedom for the tube abutment block 29 adapted to support and engage a tube end when producing compound bends.

A modification of the tube abutment block of FIG. 2 is shown in FIG. 7. Thus, whereas the tube abutment block 29 of FIG. 2 is fixed to or integral with the support rod 26, the embodiment of FIG. 7 adds an additional degree of freedom by means of a pivotal connection between the tube abutment block and the support rod. As is shown in FIG. 7, the tube abutment block 41 includes a single V-groove 44 in the surface thereof. V-groove 44 is defined by intersecting walls defining an included angle of approximately Depending from the tube abutment block 41 is a leg portion 43 having a transverse bore therethrough. Leg portion 43 is adapted to be received within a bifurcated end portion of the support rod 42. A pin 45 extends transversely through the bifurcated end portion of the support rod 42 and the leg 43 of the tube abutment block. A spring 46 and detent pin 47 are received within a recess of the support rod such that the detent pin 47 is biased into engagement with the leg 43 to retain the tube abutment block 41 frictionally in any desired orientation relative to the support rod 42.

The pivoted tube abutment block 41 of FIG. 7, therefore, adds a degree of freedom to the tube abutment block as shown in FIG. 2 thus permitting a single V-groove 44 (FIG. 7) to be orientated into virtually an infinite number of positions in order to provide finn support regardless of the degree of bend with which the tube has been initially provided.

It may now be seen that this invention makes it possible to employ an otherwise conventional tube bending tool to place compound bends in a length of tubing. As illustrated in FIG. 2, the tubing 30 has a bend already placed in it by the bending tool in a conventional manner. FIG. I shows tubing 30 in place prior to making a first bend. Assuming it is desired to place a second bend in the tubing in a plane other than the plane of the original bend, the operator need merely adjust the elements of the tube abutment means 22 so that the periphery of the previously bent tubing 30 will be received on the tube abutment block 29 (FIG. 2) and supported in this position for a subsequent bend. The embodiment of FIG. 2 permits adjustment of the tube abutment block 29 in a number of ways. The block carrier 24 may be rotated about the bar 20. The block carrier 24 may also be moved along the bar 20 as shown by the arrow direction 35. The support rod 26 may be rotated about its axis. The support rod 26 may also be translated with respect to the block carrier 24. The embodiment of FIG. 7 adds another degree of freedom to the tube abutment means of FIG. 2 in that the tube abutment block is pivotally secured to the support rod.

For ease of description, the principles of the invention have been set forth in connection with but a single illustrated embodiment. It is not our intention that the illustrated embodiment nor the terminology employed in describing it be limiting inasmuch as variations in these may be made without departing from the spirit of the invention. Rather, we desire to be restricted only by the scope of the appended claims.

We claim:

1. In a tube bending tool comprising a base, a shaft rotatably supported on the base, a forming mandrel secured to the shaft, an elongated bar secured at one end to the forming mandrel, tube abutment means supported by the bar, the tube abutment means comprising:

a tube abutment block having at least one tube engaging groove thereon;

the improvement in a support means for mounting the tube abutment block to the bar;

said improvement comprising:

a support rod extending through said tube abutment block and having an axis parallel to the bar; a block carrier adjustably supported by the bar; and means adjustably securing said support rod to said block carrier such that said support rod and said tube abutment block may be rotated about an axis of rotation of said support rod, and said support rod and said tube abutment block may be moved toward and away from said block carrier.

2. The invention of claim I in which said support rod is further defined as a cylindrical member secured to said abutment block, said rod being disposed within a bore of said block carrier.

3. The invention of claim 1 in which said abutment block includes a tube engaging surface defined by at least one V- shaped notch.

4. The invention of claim 3 in which said abutment block includes a plurality of V-ahaped notches in the external surface thereof, the walls defining said notches intersecting in lines of intersection disposed at a plurality of angles with respect to v section of the walls defining said notch may be oriented in a plurality of positions with respect to the axis of said support rod.

7. The invention of claim 6 in which said support rod includes a spring-biased detent in engagement with said abutment block.

8. The invention of claim 1 in which said block carrier includes a pair of bores therethrough and said bar and said support rod are disposed within said bores with their respective axes parallel.

9. The invention of claim 8 in which said block is provided with locking means to secure said support rod and said bar to said block. 

2. The invention of claim 1 in which said support rod is further defined as a cylindrical member secured to said abutment block, said rod being disposed within a bore of said block carrier.
 3. The invention of claim 1 in which said abutment block includes a tube engaging surface defined by at least one V-shaped notch.
 4. The invention of claim 3 in which said abutment block includes a plurality of V-ahaped notches in the external surface thereof, the walls defining said notches intersecting in lines of intersection disposed at a plurality of angles with respect to the axis of said support rod.
 5. The invention of claim 4 in which said abutment block includes at least three V-shaped notches in the external surface thereof, the walls defining said notches intersecting in lines of intersection disposed at angles substantially of 30*, 45*, and 60* with respect to the axis of said support rod.
 6. The invention of claim 3 in which said abutment block is pivotally secured to said support rod whereby the line of intersection of the walls defining said notch may be oriented in a plurality of positions with respect to the axis of said support rod.
 7. The invention of claim 6 in which said support rod includes a spring-biased detent in engagement with said abutment block.
 8. The invention of claim 1 in which said block carrier includes a pair of bores therethrough and said bar and said support rod are disposed within said bores with their respective axes parallel.
 9. The invention of claim 8 in which said block is provided with locking means to secure said support rod and said bar to said block. 